<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	</head>
	<body>
		<script>
			var arr1 = [1,2,3];
			var arr2 = new Array(1,2);
			
			var str1 = new String("abc");
			var str2 = "abc";
			
			console.log(arr1 instanceof Array);
			console.log(Array.isArray(arr2));
			console.log(Array.isArray(str1));
			console.log(str1 instanceof String);
			console.log(str2 instanceof String);
			
			var stu = new Stu();
			function Stu(){
				
			}
			console.log(stu instanceof Stu);
			
			console.log(arr1);
			console.log(arr1.toString());
			console.log(typeof arr1.toString());
			console.log(arr1.valueOf());
			console.log(typeof arr1.valueOf());
			
			var arr = ["关羽","张飞","刘备"];
			var str1 = arr.join();
			var str2 = arr.join(" ");
			var str3 = arr.join("");
			var str4 = arr.join("&");
			console.log(str1);
			console.log(str2);
			console.log(str3);
			console.log(str4);
		</script>
	</body>
</html>
